The present invention relates to a lamp socket for locating an electric light source that has a screw-threaded base, such as a light bulb or a light tube generally known as an energy saving lamp.
In order to hold an electric light bulb or tube having a screw-threaded base, a typical lamp socket includes a receptacle in which a screw-threaded collar is located. Conventionally, the collar is made of copper or copper alloy that is electrically conductive, for direct electrical connection with the base as one terminal.
The process of making a screw-threaded metal collar is relatively complicated and/or time consuming, usually requiring separate processes in production for the formation of the body of the collar and the formation of screw threads therein. Also, copper, like most other metals, is relatively or becoming expensive.
The invention seeks to mitigate or at least alleviate such problems and shortcomings by providing an improved lamp socket.
According to the invention, there is provided a lamp socket for holding at least one electric light source having a screw-threaded base, comprising a body defining therein a receptacle for receiving and locating a said light source by its base about an axis, and at least two separately moulded part-cylindrical socket members located within the receptacle and arranged in an annular manner about the axis. The socket members have on their inner surfaces screw threads for engaging the base of a said light source. A pair of electrical contacts is arranged within the receptacle for contact by respective side and end terminals on the base of a said light source. The body is formed by two separate parts, with the first part formed with an aperture to define an open end of the receptacle and the second part having a solid wall to define a closed end of the receptacle.
It is preferred that each socket member has a body of a thickness similar to the depth of its screw threads.
Preferably, the socket members have substantially the same construction as one another.
More preferably, each socket member has opposite arcuate edges and its screw threads are formed at a substantially central position between the two edges.
The socket members may be located within the receptacle at different levels with respect to the axis such that their screw threads at opposite ends are aligned as between adjacent socket members.
In a preferred embodiment, a pair of said socket members is incorporated, which are located on diametrically opposite sides within the receptacle.
More preferably, each socket member extends over an angle slightly short of 180xc2x0.
It is preferred that the socket members are arranged in an annular manner to form substantially a split collar.
In a preferred embodiment, the receptacle has a generally cylindrical inner surface formed with part-cylindrical recesses locating therein the socket members respectively.
More preferably, opposite ends of each socket member and the corresponding recess have respective inclined surfaces for inter-engagement to hold the socket member in the recess.
It is preferred that each socket member has opposite arcuate peripheral sides that are asymmetrical compared with each other and the corresponding recess has a matching shape, whereby the orientation at which the socket member is fitted within the recess is determined.
It is further preferred that one arcuate peripheral side of each socket member is formed with a notch and the corresponding recess is formed with a protrusion matching with the notch for engagement therewith to determine the orientation at which the socket member is fitted within the recess.
In a specific construction, the lamp socket is for holding two said electric light sources, in that the body has opposite ends defining two said receptacles facing in opposite directions for locating said light sources respectively, with a first end of each body part formed with a said aperture to define an open end of one receptacle and a second end of each body part having a said solid wall to define a closed end of the other receptacle.
More specifically, the two body parts have substantially the same construction as each other.
It is preferred that the body and the socket members are moulded from plastics material.